Field of Use
This disclosure is generally directed to surface layers for fuser members useful in electrophotographic imaging apparatuses, including digital, image on image, and the like.
Background
Generally, in a commercial electrophotographic marking or reproduction apparatus (such as copier/duplicators, printers, multifunctional systems or the like), a latent image charge pattern is formed on a uniformly charged photoconductive or dielectric member. Pigmented marking particles (toner) are attracted to the latent image charge pattern to develop this image on the photoconductive or dielectric member. A receiver member, such as paper, is then brought into contact with the dielectric or photoconductive member and an electric field applied to transfer the marking particle developed image to the receiver member from the photoconductive or dielectric member. After transfer, the receiver member bearing the transferred image is transported away from the dielectric member to a fusion station and the image is fixed or fused to the receiver member by heat and/or pressure to form a permanent reproduction thereon. The receiving member passes between a pressure roll and a heated fuser roll or element.
Fluoropolymers have utility in a variety of applications due to superior chemical and thermal stability, as well a low coefficient of friction. Fluoropolymers are thermally insulating and thus heat transfer through a fluoropolymeric coating is poor.
Higher fusing speed can be achieved by increasing the thermal conductivity of the surface layer of the fuser member. Increased thermal conductivity of the fuser surface also allows for a lower fusing temperature and a wider fusing latitude. Various thermally conductive fillers have been disclosed for increasing thermal conductivity of the fuser surface. Carbon nanotubes (CNT) having a fluoroelastomer sheath dispersed in a fluoroplastic are described in U.S. Pat. No. 7,991,340. However, carbon nanotubes are costly to produce and available in relatively small quantities compared to other bulk chemicals. In addition, the production of carbon nanotubes is energy intensive. Furthermore, the impact on the environment and human health from long-term exposure to freeform carbon nanotubes is unknown. Fuser surfaces having increased thermal conductivity without negatively impacting fusing performance are desired.